All 'obj:method' calls must pass 'obj' as the first parameter to function, no metter what type 'obj' is. So it's extremely wierd if it doesn't. I haven't tried this on objects, but it works well with strings and numbers. Maybe I couldn't understand what your problem is.
I'm curious about why following does not works:
Lua 5.1.4 Copyright (C) 1994-2008 Lua.org, PUC-Rio
t={'a','a'}
print(t:concat())
stdin:1: attempt to call method 'concat' (a nil value)
stack traceback:
stdin:1: in main chunk
[C]: ?
Blessings!
--
Fernando P. García,
http://www.develcuy.com
Developer - Analista de Sistemas
+51 1 9 8991 7871, Calle Santa Catalina Ancha #377, Cusco -Perú
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